Since the birth of notebook computers, many types of small-sized computers have been produced. A common problem associated with the smaller size, however, is that miniaturized input/output devices (such as keyboards) can be cumbersome, slow and uncomfortable to use.
The personal digital assist (PDA), which is typically smaller than a notebook computer, has become very popular in recent years. PDAs typically include a liquid crystal display (LCD) for receiving input and displaying information to the user. Unlike the conventional desktop computer, a PDA does not typically have a conventional keyboard, and has only limited control buttons thereon and a stylus that can be used to input data on the display. The PDA may store handwriting in bitmap or another graphical form, but this technique is typically cumbersome to process, requires a large amount of memory and lowers the efficiency of the PDA. Another method for inputting data to a PDA involves handwriting recognition software installed in the PDA. The PDA encoder translates handwriting to ASCII or another alphanumeric code, and then stores the alphanumeric data. Alternatively, the PDA may have a virtual keyboard. When the virtual keyboard is displayed on the screen, a user can utilize the stylus or control buttons to activate keys within the virtual keyboard to input data.
Conventional input methods for PDAs, however, are not typically as efficient as using a conventional computer keyboard. A typical PDA does not include a conventional keyboard because of relatively large size of the keyboard. Various forms of externally-connectable keyboards have been fashioned to work with PDAs, however. When a user wants to input data, the user connects the separable keyboard to the PDA for rapid data entry.
There are at least two types of the conventional separable keyboards for PDAs. One type is similar to the conventional computer keyboard, but smaller in size. The other is a foldable keyboard whereby a keyboard is separated into at least two parts that are foldably connected to each other. When the foldable keyboard is not in use, it can be folded and conveniently stored.
Miniature external keyboards for portable electronic devices are generally smaller than conventional desktop keyboards to improve portability. The external keyboard is typically connected to the PDA so that the user can hold the keyboard in his/her hands and input data with his/her thumbs. The connection between the external keyboard and the PDA is typically highly determinative of the user's comfort during data input. If the connection is weak, then extra care in handling may be required to prevent the keyboard from detaching from the PDA.
Moreover, the connection mechanism of the PDA and the keyboard has not adjustable, meaning that any particular keyboard design is useable with only a specific PDA design. As many brands and models of PDA become increasingly available, it is a desire to provide a data input apparatus that is able to detachably connect to multiple brands and models of PDAs in a reliable manner.